Safety device for elevators



l 2 Smets-sheet 1. A. C. ELL1THORPE.

SAFETY DEVICE POR ELEVATORS.

(No Model.)

' Patented Oct. 11,1881.

WITNESSES l ATTORNEYS.

- 2 Sheets-Sheet 2.

(No lsaoel.)l

A. C. ELLITHORPE.

SAFETY DEVICE POB ELEVATORS..

` No. 248,150. Pten'd Oct. 11,1881."

' -A INTOR:

` WITNBSSES:

ATTORNEYS.

i UNITED STATES PATENT (")FFICEN` ALBERT C. ELLITHORPE, 0F CHICAGO, ILLINOIS.

SAFETY DEVICE ,FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 248,150, dated October 11, 1881.

Application tiled March 23, [881. (No model.)

To all whom It may concern of Chicago, Cook county, Illinois, have invented a new andv useful Improvement in Safe'- ty Devices for Elevators; and I do hereby declare that the' followingis a full, clear, and

exact description ot' the same, reference bein g had. to theaccompanying drawings, forming part ot' this specification, in which- Figure l is a side elevation ot' .my improved elevator. Fig. 2 is a bottom view of theelevator-car and brake mechanism. Fig. 3 is a f forth.

In the accompanying drawings, A A represent the guide-posts, and B the elevator-car, both of ordinary construction, and operated, in the usual manner, by means of' the rope C and pulley D.

V represents an auxiliary air-shaft open at bottom, and provided with a Hap-valve, W, opening upward, and guides o for the cage T, adapted to reciprocate in the shaftV.

The cage T is hollow and Square in crosssection and adapted totit loosely in the auxiliary shaft V.

Y Yare iiexible valves fitting over the heads in the ends of the lcage T, and each provided with springs a, secured to the heads of the cage and bearing against theV under faces of the valves to press the upper valve upward and thelower valve downward somewhat into acu'p form.

b is an eyebolt secured centrally in 4the upper head ot' the cage T, to which the cable Q is securely fastened. The cable Q passes from the eyebolt b up and through a central opening in the upper head of the shaft V, thence around pulleys S S, and thence downwardly outside the elevator-car B, partly around a small pulley, R, as shown in Fig. 1, secured to ,fthe bottom of the car, and `is attached Ito. vthe Beitknown that I, ALBERT C. ELLrrHoRPE,

end of the trip-link O, having a central longitudinal slot, o, which receives the free end ot the trip-lever M, pivo'ted to the bottom of the 55 ear at c.

To the outer end of the Irip-link O is secured a rope, P, the-opposite end of which is secured to an eyebolt or lug securely attached to the bottom of. the elevator-car.

E E representt'our brake-levers, f'ulerumed at G to the plates Z,secured to the bottom of the car-elevator B, as shown in Fig. 2. The brake-levels E are each provided on its outer end with a brake-shoe, H, pivoted at F to the brake-lever, and adapted to clamp the guideposts A when operated.

. The inner endsof the brake-levers Eare each provided with a projectin g lug, d, adapted to be received in a recess between the jaws L 7o L, secured to the tripllever M.

K K are semi-elliptic springs secured to the bottom of the elevator car, each between a pair of brake-levers, the spring acting to throw the inner ends ot' the brake-levers outwardly `75 when released from the trip-lever M, andthe brake-shoes to bite or clamp the guide'posts.

In Fig. 4, I have shown the brake mechanism as applied to the top ot' thecar-elevator. In lieuot the semi-elliptic springs K, above de- 8o scribed, for operating the brake-levers, other forms ot' springs may be'employed or any similardevice for operating the brake-levers.

The auxiliary shaftV is preferably arranged parallel-with and near the guide-posts A, althouglrit maybe arranged at any distance from the elevator without departing from' the spirit of my invention.

It will be observed from the -arran gement an construction of the parts as above described 9o that as the elevator-car ascends the cage inthe auxiliaryv shaft descends, and vice versa, and the valves Y are so arranged that in the ascent and descent of the cage T, when it and the elevator-car are moving at the ordinary rate of speed, the valves will not be pressed outward bythe resistance of the air in the shaft V, but will assume the positions shown in Fig. l. If, however, the'elevator-car, from any cause, is moving wit-h too great velocity roo downward, for example, or the rope C should break, a corresponding vincrease of velocity is imparted to the cage upward, and the resistance of the air in the shaft V between the cage and the head of the shaft will press out the upper valve Y, preventing the escape of air down the sides ofthe cage T, thus imparting au increased strain on the cable Q sufficient to break the smaller cable, P, between the slotted trip-link O and its attachment to y the bottom of the elevator-car, whereby the trip-lever is swung, the brake-levers released, andthe friction-shoes clamp the guide-posts at either side, actuated by the springs.

In the upward movement of the eageT the nap-valve W opens to admit air to prevent a tendency to form a vacuum below the cage.

In the downward movement of the cage, in case of the breakage of the connection P, as before described, the valve W will be closed by the pressure of the airabove N, and the resistance of the air in the space between the upper face of the Hap-valve W and the lower end of the cage will press the lower valve Y upward and outward against the interior sides of the shaft V, and an air-cushion will thus be formed at the lower end of the cage to allow it to descend easily to the bottom of the shaft.

The object of making the cage T hollow is to introduce suiieient weight to secure proper tension to the cable Q and insure the descent of the cage in the auxiliary shaft V.

What I claim as my invention is l. The combination, with an elevator-car provided with a brake mechanism, of an auxiliary air-shaft, a cage reciprocating in said shaft and provided with an upper and lower valve operated by the resistance of air in the shaft, and a connection between the cage and elevator-ear adapted to be broken or detached by the resistance of the air when an accelerated speed is imparted to the car, substantially as described.

2. The combination, with an elevator-car, B, of the pivoted trip-lever M, having jaws L, brake-levers E, provided with brake shoes H and lugs d, guide-posts A, springs K, and slotted trip-link O, secured to the car by the detachable cord P, substantially as described.

3. The combination, with the guide-posts A and elevator-car B, provided with the triplever M, havin gjaws L, brake-levers E, springs K, slotted trip-link O, and detachable cord P, of the cable Q, air-shaft V, and cage T, provided with the upper and lower spring-valves, Y, substantially as described.

4. The hollow cage T, provided with upper y and lower heads, valves Y, and springs a, substantially as described.

5. The combination, with the auxiliary' airshaft V, provided with guides t and `valve W, of the hollow cage T, provided with upper and lowerheads, and spring-valvesY, substantially as described. y

6. In an elevator or inclined-way safety de vice, a balanced cord secured at one end to a cage reciprocating in an auxiliary airshaft, and attached at its other end to the elevator car by a cord adapted to break and allow the brakes to be applied to the guide-posts, sub-A ated motiou of the car, whereby, if the liftingrope of the elevator-car breaks, the movement of the car will be retarded by the resistance ot' thc air in the shaft on the expanding upper valve, substantially as described.

ALBERT C. ELLITHORPE. lVitnesscs:

Unas A. Pn'r'rrr, Anios W. HART. 

